not applicable
not applicable
not applicable
The invention concerns a pneumatically operating distribution machine.
Pneumatically operating distribution machines have long been known and serve, among other things, to spread seeds or fertilizer. These distribution machines known from practice display a storage container for the goods to be distributed, and, following this, a metering of the goods to be distributed takes place by means of a metering element, and subsequent to this there takes place, via a pneumatic delivery line, a pneumatic delivery of the goods to be distributed to a distributor, from which, in turn, lines lead to the individual spreading elements.
Especially in the case of larger distribution machines, the pneumatic delivery line at first runs in an essentially horizontal direction, and afterward there results a change in direction of the delivery line towards the distributor arranged further above, so that before reaching the distributor the delivery line is essentially vertically oriented.
At this point of change in direction of the delivery line from an initial level running to a vertical rising towards the distributor, there occurs a concentration of the seed grains in the conveying air stream at the outside wall of the bend, due to the twisting, usually present, of the current in the delivery line and due to the centrifugal forces. Through this concentration, a completely uniform distribution of the seeds in the distributor and subsequently in the lines coming from the distributor to the spreading elements is impeded.
Corrugated tubes or other fittings in the vertically-designed conveying tube underneath the distributor head are not capable of again dispersing the unbalanced seed stream in the relatively short stretch between the bend of the delivery line and the distributor head.
Solutions have been developed, e.g. corresponding to DE-PS 22 56 939, to again disperse, through baffle plates built into the bend, the grain stream before the entrance into the vertical delivery line. These bends equipped with baffle plates are, however, disadvantageous, since the radius of curvature of the bend must be relatively large in order to keep the flow losses small, and through the baffle or deflecting plates the total resistance of the bend is considerably increased; furthermore, with different seeds there is the possibility of damage to the grains. Baffle or deflecting plates are also disadvantageous due to the fact that when they are arranged in the center of the air current, they do not ensure an optimal distribution, since a concentration of the goods to be distributed occurs on the outer side of the curve, so that the central baffle plate catches only about a third of the grain stream.
The object of the invention is to create a pneumatic distribution machine of the generic type that makes possible an improved distribution of the seeds inside the vertical delivery tube to the distributor, without using baffle or deflecting plates, which have the above-mentioned disadvantages.
This object of the invention is achieved through the use of an essentially vertical dispersing tube defining a turning point therein. The dispensing tube has an unevenly formed inner wall. The dispensing tube also has a flat tube bend at its turning point.
In other words, it is proposed that in the region of the change of direction of the pneumatic delivery line, i.e. from a level-running region into a region rising to the distributor, the pneumatic delivery line be provided with a cross section differing from the shape of the delivery means attached to the exit of this region.
Advantageous configurations of the invention include, but are not limited to, the following.
The cross section of the flat tube bend may be rectangular, or may be oval.
The delivery line may have an asymmetrical junction of the flat tube bend with the dispersing tube. In such cases, the outer-curve wall of the flat tube bend may be parallel with a central axis of the flat tube bend.
At least a part of the inner surface of the flat tube bend may be unevenly formed.
The cross section of the delivery line leading to the flat tube bend may be circular. Likewise, the cross section of the delivery line leading from the flat tube bend may be circular.
The dispersing tube may be a corrugated tube.